Antifriction bearing and method of producing the same



May 13 1924.

R. T. COLE ANTIFRICTION BEARING AND METHOD OF PRODUCING THE SAME Filed Sept. 25, 1919 Em. H

PIBIV V. .7 1 w r El ll FIEV ETEIIII Patented 13,19 24.

UNITED srATEs PATENT "oF.F 1cE.

sermons r. cons, or woacss'rns.. mnssscnussrrs, ASSIGNOR romnssncnussrrs onmrss BEARINGS conronarron. or wnxsrmnn, mnssnonusn'rrs, A consona- TION- F MASSAGHUSETTS.

m'nrnrc'nou ammo AND ian'rnon or raonocme 'rnn sum.

Applicationlflled September at, 1919: Serial no. 326,196.-

' To ail whom it may concern.

Be it known that L RAYMOND T. Cons, a

I "citizen of the United States, and resident of Worcester, in the county of Worcester 5 and State of ,Massachusetts, have invented anImprovemen't in Antifriction Bearings and Methods of Producing the Same, of

which the following description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings representing like parts.

This invention relates to an anti-friction or self-lubricating bearing for moving arts of machinery, and to a method of ma g M the same. I

In United States Patent No. 1,022,465.,

granted to me April 9, 1912, I have -described a material for self-lubricatin bearin composed of graphite unifor y d1sm-tri uted through a metal matrix, and a -method of pro ucing such material and of making bearings therefrom. I The object of the resent invention is to produce a bearing w ich while having the as self-lubricating property and character of the bearing described in said prior atent may be made of greaterstrength an may have certain other rop'erties which will hereinafter set fort which do not pertain 80 to the bearing forming the subject of my I previous invention.

The hearing forming the subject of the present invention is a compound bear ng and consists of an inner portion or hnmg composed of graphited matrix material such as set forth i myformer. patent a bove mentioned, whic is surrounded by and 'integrally united to-a metallic body portion which may-be of any suitable metal or alloy of metals such as bronze or brass.

The method of roduction by which the in al union of t e7 aphited matrix materia and body me is effected will be hereinafter set forth.

4 Fig. ,1, is a transverse section'- on line as Fig. 2 of a compound bearing piece embodying this invention, suitable for a bearing for a trolley wheel forming a part of an electric circuit.

Fig.2, a longitudinal section thereof on line a2. Fig.1. Fig. 3, a side elevation of the self-lubricating inner portion or of the'bearing as it appears before being incorporated in the comp ete bearing.

Fig. 4, a longitudinal section of a similar bearing in which no provision for' enhanced electric conductivity is made, and

Fig. 5, a sectional view illustrating a step in the method of production.

A compound bearing of the construction shown in Figs. 1 and 2 is specially useful "where enhanced electric conductivity is re-' quired, as for example, in the bearing of a trolley wheel of an electric car.

The compound bearing 1s composed essentlally of an mternal or lining portion 2 of graphited matrix material such as forms the subject of-my prior patent, No. 1,022,465, and-a metallic bodyportion. 3 surrounding and enclosing said'internal portion and integrally unite or welded thereto as will be hereinafter described.

Whenthe hearing has to. serve -only the mechanical function of supporting a moving part, such as a rotating shaft, the internal portion 2 which affords the bearmg surface may be made as a complete tube, or with an uninterrupted bearingsurface as shown in Fig. 4; in which construction the metallic bo y portion 3 enhances the strength of the bearing, and may be made of any desired form or shape of external.

surface, while only a-"suflicient portion of the graphited matrix material to afford an effective' and lasting self-lubricating bearing portion need be used.

In some cases, itis desirable to provide for electric conductivity from the bearing portion to the part supported thereby as in the case of the bearing for thetrolley wheel of an electric car, and in such cases the.

construction shown in Figs. 1 and 2 provides the necessary propert In this construction the internal portion of the hearing which iscomposed of the graphited matrix material isprovided with a number of perforations 4, and the body portion 3 has projecting portions 5, which v enter the said opemngs 'andcoincide with the mner bearlng'surface of the internal portion4, and thus provided for. making contact from the hody portion 3 of the bearingzho thev shaft or part running therein.

ether for purely mechanical purposes, or for also prov1dmg for electric conduc- 1 tivity, the body portion 3 may be of any 7 suitable metal such as brass or bronze, or

even pure copper, although some ofthe cop per alloysare generally most desirable for thepurpose.

The production of the bearing 'inaccordance with one portion of the present invention involves the method by which the graphited matrix is produced as set forth in my former patent and is based upon a discovery I have'made of a certain prop.- erty of said graphited matrix material which would not naturally 'be' expected to' characterize the same.

Briefly stated the method of' making a bearin from the graphited matrix'fcrmlng the su ject of my prior patent, comprises metal havin a relatively the coating of'particles of graphite with a high melting. point and then distributing the same through a molten metal having a relatively low melting point, and casting the resultingmixture under a high pressure.

' In actual; commercial. practice, the graphited matrix material is cast in dies under av pressure of several tons to the square inch.

I have discovered that whilethe'metal matrix portion of a bearing piece produced as just'described may have a comparatively low melting point, the casting'made therefrom, after it has been cooled, cannot be melted at a much higher heat, having approximately 7 .the heatv resistance of a graphite crucible material.

Accordingly in order to produce the compound, or reinforced self-lubricating bearing, as it maybe called, forming the subject of the present invention, the internal portion2 which is to afford thebearing SlllY-i face is first made by the process of my prior patent, by coating the flakes of graphite 'and solidified is introduced into 'a mold -3 of the bearin'g'is to be made is then with. a metal, such for example, as cop er, having a'relatively high melting point, t en a mixing said coated flakes with a metal, such as Babbitt metal, having a much lower melting point,' and then die-casting the mixture under pressure to' the form desired for the internal portion or lining of'the compound or reinforcedbearing tobe roduced.

.Said internal portion w en it is cooled such as indicated at 6 in Fi' 5 and the metal of which the external or. dyportxzli 1i in molten condition into 'the said mo dfand into contact-with the surface of theinternal piece2.' The metal of the bod portion, although it may be at a muchbig or temperature thanthe melting point 'of the metal matrix of the internal bearing piece does not fuse the same, owing to the refractory nature of the latter above stated, but along ,the surface at which it'makes contact there-isa localfusing action which results in an alloyopenings to the bearing surface and grally' 'um ing of, or integral union between the two components of the bearing, "which i'sjan important characteristic of the com 'lete bearlng and one which could not be 0 tained by.

the usual process of casting a more easily fusible metal on toa more'refractory one.

Where the inner component- 2 of'the bear ing is in the form ofa tube as in the illustration herein-shown,.said component may be placed upon an iron core as shown at 7, Fig. 5, whe'n in .the mold 6 to facilitate the. proper casting of the body metal upon the form required for the finished compound bearin piece.

Whi e a bearing of the kind herein 'degraphited matrix portion, and it is obvii one that the mold 6 may be of any suitable shape according to the external shape orscribed is self-lubricating, and will run ef- .fectively without. oil or with only a very slight amount of v oil, it may through ignorance or inadvertence be supplied with-an excess of'lubricant'which has a tendency to 'softenor disentegrate the gfaphitedmatrix material, and in such case t e metallic body portion ofthe compound bearing being uhaffected by the lubricant tends to prevent, I the disintegration or breaking up of the graphited portion while the inte al'union throughout a metal matrixhaving a rela-. tively lowfusing temperature, and. a surrounding body portion of metal having i1 relatively high fusing temperature, integrally united with the said matrix metal.

2.1A bearing consisting of an internalv tubular portion affording va bearing surface composed of graphite particles distributed throughout a matrix metal havin a' 'relatively low fusing temperature and having a body portion of metal 'havmg a higher fusing temperature surrounding and -.inte ally united with the" matrix metal of said internal portion andhaving portions projecting v I through said internal portion and afiording do apart of the bearing-surface.

3. An anti frictionib'e an internalportion alfordin the boil surface and composed ofsma particles ,0

graphite distributed. thro" hout,a matrix a relatively ow fusing temseparated-from one another i y; said matrix metal anda metallic body I I metal ha piece consisting of portion having a higher fusing temperature surroundigfi said internal-portion and inteiaiaf e he t I 4. The process of forming a compound ing a higher melting temperature into said anti-frictionbearing which consists in first mold to ,cast the body portion of the com- 1 making a casting from graphited matrix pound bearing and cause the same to become material composed of graphite particles (lisintegrally united with the internal portion.

5 tributed throughout a metal matrix having In testimony whereof, I have signed my a relatively low melting temperature; inname to this specification. troducing said casting into a mold, and pouring molten metal or metal alloy hav- RAYMOND T. COLE. 

